Methamphetamine (MA) abuse is the fastest growing drug problem in the United States and is responsible for significant public health complications, including HIV infection1. As a result effective treatments for MA dependence are urgently needed. There are currently no efficacious medications for MA dependence, although results from preliminary randomized trials of bupropion for MA dependence found bupropion to be more effective than placebo, but only among subgroups of participants, including those with lower frequency of MA use at baseline 2, 3. A growing body of preclinical and clinical studies suggest that cholinergic mechanisms play an important role in the neurobiology of MA and other stimulant dependence, such as nicotine dependence 4. Mechanistically, cholinergic medications may alleviate MA-associated cognitive dysfunction, thereby improving outcomes of treatment for MA dependence 5. Varenicline is a partial agonist at α4β2 nicotinic receptors and a full agonist at α7 nicotinic receptors that has been approved as an anti-cigarette smoking medication. In order to assess the potential efficacy of varenicline for methamphetamine dependence, we will perform a clinical trial to assess the following aims: